Reenforced sounding board



Dec. 30, 1930.- M. R. HUTCHISON ,0

I REENFORCED SQUNDING BOARD Filed March 15, 1927 INVENTOR. MILLER REESE HUTCHISON ATTORNEY I LER REESE nu'romsom or .IJLEWELY of course,

for impressing thereon Patented Dec. 30, 1930 i NITED STATES PATENT OFFICE? f N P RK, wns'r ORANGE, NEW JERSEY, AS-

. gSIGNOR, BY MESNE ASSIGNMENTS, 'ro Aoous'rrc rnonucrs COMPANY, or NEW YORK, 1v. Y4, A CORPORATION OFDELAWARE i nnnnroncnn SOUNDING BOARD Application filed March 15, 1927. Serial No. 175,456.

This invention relates to improvements in sounding boards. 1 The invention has for its principal object the provision of an improved sounding board for efficient propagation of the lower notes ofthe musical register. V

Inmy copending 'applicatioInSerial No. 159,135 filed Jan. 5, 1927, for method and means for producing compressional waves,

I have disclosed an instrument for the faithful reproduction of musical sound embodying twelve tunedunits corresponding to the notes of one of the lower middle octaves. These units are arranged to respond accurately to any oscillation corresponding to their fun-' damentals, and to all the overtoneswhich, include the higher octaves. In said prior application, I pointed out, however, the necessity forproviding other means for producing the notes of lower register; and one such means consists in the association with twelve such units of a vibrating or sounding body primarily responsive only to such lower notes.

An important feature of the present invention relatesto the provision of a sounding board having one or more intermediate, ribs or rods, each having a relatively low natural period of vibration, in combination with contiguous wings or webs actuated thereby for impressing compressional wave energy upon a surrounding natural medium.

Another feature relates to the tuning of such a rod or rib to one predetermined musical note of the scale, and to the provision of an additional rod or rib tuned to a different note of the musical scale.

Another feature relates to the provision of a sounding board, having a reenforcement rib in combination with an electromagnetic unit controlled by electric undulatory energy vibratory energy of similar wave form.

Another feature relates to the provision of a sound propagator having portions of relatively different thickness, tions being flexed into circular cross section.

Another feature relates to the provision of adjustable supporting means for positioning the electromagnetic unit with respect to the the thinner porsounding propagator to obtain maximum effectiveness in impressing vibratory energy thereon.

Other objects of the invention will appear from the following description taken in connect-ion with the accompanying drawings, in which i v i Fig. 1 is a side elevation'of one form of sound propagator embodying features of the invention;

Fig. 2 is a front elevation thereof;

Fig. 3 is a cross-section taken on the line 3-3 of Fig 2; V

Fig. 4 is a cross-section of a modified form having the sounding board flexed trans versely; and

Figs. 5,6 and? are cross-sectional views of additional modified forms of the inven tion. s i I Like reference characters denotelike parts in theseveral figures of the drawings.

5 In the following description and claims, parts, characteristicfeatures and functions will be identified by specific means for co11- venience of expression, but they are intended to be as generic in their application to similar par-ts or equivalent construction as the art will permit.

Referring tot-he forms of'the invention shownin Figs. 1, 2 and 3, there is provided a base 10, and a top piece 11, spaced therefrom and parallel therewitln Interconnecting the top piece 11 and the base 10 is a supporting rod 12, and a vibratory element or soundjpropagator 13. An electromagnetic unit 1 1 is ,slidably mounted as by a clamp 15 on the supporting rod 12, and includes a rod 16 forming an operative connection from the unit 14 to the sound propagator 13. In the form illustrated, this operative connection extends to a'point 17 on the sound propaga- 'tor 13 substantially fifteen percent of the length: of the sounding board from its end. The-sounding board 13 is shown as in Fig. 1 to be slightly bowed or flexed longitudinally into circular cross-section. It is undcrstood that the electro-magnetic unit 14 is electrically controlled'from a source of electricundulatory energy (not shown) such as a radio receiving set or public address systen'i, or the like.

The sound propagator 13 is shown as including a longitudinal enlarged portion 20 forming a rod or rib and preferably the point of application of the vibratory energy is on the line of the rod 20. The adjusting or con tiguous portions 21, 22 of the vibratory ele ment 13 form webs or wings of considerable superficial area in contact with the surrounding natural medium, and thus vibratory energy impressed uponthe rod 20 is communicated to the contiguous portions of the sounding board and efficiently impressed upon the surrounding air.

The modified embodiment shown in Fig. 1 includes a sounding board 113, which instead of being bowed longitudinally, as in Fig. 1, is flexed transversely.

In the modified embodiment shown in Fig. 5, the vibratory element '13 and the electromagnetic unit 1 1; isprovided as in Fi gs. 1 and 2, and an enlarged portion forming a rod or rib 220 is provided. The enlarged portion 220 is rectangular in cross-section. In the modified form shown in Fig. (i, the parallel spaced longitudinal rods or ribs 320, 3:23 are provided, each having an electron'iagnetic unit 314:, 318 for actuating the same. Thus there are provided three web portions of reduced thickness as at 321, 322, 324 for elliciently impressing theviln'atory energy upon the surrounding atmosphere.

In the modified form shown in Fig. 7 there are provided three longitudinal ribs or webs as at 420, 123, 4:25 having a corresponding plurality of electromagnetic units 11 1, 418, 419 for impressing vibratory energy thereon. Thus there are formed a plurality of webs or wings 421, 422, 4:24, 126.

Each longitudinal rod such as the rod 20, or the rods 420, 423, 425, may be independently tuned so as to have a relatively difi'erent natural period of vibration. Thus musical sounds of corresponding pitch may be efficiently propagated.

In operation, it is understood that the electromagnetic units 14:, 314;, 318 etc. are controlled from a source of undulatory electrical energy of complex wave form, having components of relatively low frequency corresponding to the lower notes of the musical register. In case the present sound propagator forms part of a device ofthe form illustrated in general in the copending application, hereinbefore referred to, it is understood that such components of low frequency will be selectively impressed upon the electromagnetic units herein designated. Each electromagnetic unit thus produces movement of its respective rod 16, and of the sounding rib connected thereto. This movement is communicated to the contiguous thinner portion of the sound propagator, and

compressional waves are thus produced in the surrounding atmosphere.

The invention upon which this application is based is broader than the specific embodiment shown and described for the purpose of illustrating at least one of the ways in which it may be employed. The scope of the invention is therefore to be understood as not being limited by the present specific description. I intend no limitations other than those imposed by the claims.

WVhat is claimed is:

V 1. A sounding board including a tuned rod, means for impressing vibratory energy on said rod, and a web extending from the rod and receiving the vibratory energy from said rod.

2. A sounding board including a tuned rod, a web extending from and roenforced from the rod, said rod constituting a means for connection of the web to a support, means for impressing vibratory energy on said rod for transmission therefrom to said web.

A sounding board including a tuned rod, a web, said rod being substantially straight and extending throughout one dimension of the web, said rod reinforcing the web and constituting a means of connection therefor to a support, said web having a free edge outwardly of: the support, and means for transmitting vibratory energy to said rod for transmission to said web.

1. A sounding board having portions of relatively different thicknesses, the thinner portions being flexed into circular cross-section, the thicker portion being tuned to a predetermined frequency.

In a sounding board, a reenforcement rib, and means for impressing vibratory energy on said rib at a point- 15% of the length of the rib from an end thereof.

Signed at New York in the county of New York and State of New York this 14 day of March, A. D. 1927.

MILLER REESE HUTCHISON.

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